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Related papers: Ideal approximation in $n$-exangulated categories

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Let $n$ be a positive integer. We show that an $n$-extension closed subcategory of an $n$-exangulated category naturally inherits an $n$-exangulated structure through restriction of the ambient $n$-exangulated structure. Furthermore, we…

Representation Theory · Mathematics 2026-05-14 Carlo Klapproth

Let $\mathscr{F}$ be an $(n+2)$-angulated Krull-Schmidt category and $\mathscr{A} \subset \mathscr{F}$ an $n$-extension closed, additive and full subcategory with $\operatorname{Hom}_{\mathscr{F}}(\Sigma_n \mathscr{A}, \mathscr{A}) = 0$.…

Representation Theory · Mathematics 2021-08-23 Carlo Klapproth

We define the Grothendieck group of an $n$-exangulated category. For $n$ odd, we show that this group shares many properties with the Grothendieck group of an exact or a triangulated category. In particular, we classify dense complete…

Category Theory · Mathematics 2020-12-01 Johanne Haugland

Our aim is to give a fairly complete account on the construction of compatible model structures on exact categories and symmetric monoidal exact categories, in some cases generalizing previously known results. We describe the close…

Category Theory · Mathematics 2014-07-08 Jan Stovicek

Let $(\mathcal B,\mathbb{E},\mathfrak{s})$ be an extriangulated category and $\mathcal S$ be an extension closed subcategory of $\mathcal B$. In this article, we prove that the Gabriel-Zisman localization $\mathcal B/\mathcal S$ can be…

Representation Theory · Mathematics 2023-10-13 Yu Liu , Panyue Zhou

Let $\mathscr{C}$ be a Krull-Schmidt $n$-exangulated category and $\mathscr{A}$ be an $n$-extension closed subcategory of $\mathscr{C}$. Then $\mathscr{A}$ inherits the $n$-exangulated structure from the given $n$-exangulated category in a…

Representation Theory · Mathematics 2023-10-17 Jian He , Panyue Zhou

We introduce the notion of homological systems $\Theta$ for triangulated categories. Homological systems generalize, on one hand, the notion of stratifying systems in module categories, and on the other hand, the notion of exceptional…

Category Theory · Mathematics 2013-04-22 Octavio Mendoza , Valente Santiago

Let $\mathcal{C}$ be a triangulated category. We first introduce the notion of balanced pairs in $\mathcal{C}$, and then establish the bijective correspondence between balanced pairs and proper classes $\xi$ with enough $\xi$-projectives…

Rings and Algebras · Mathematics 2021-09-03 Xianhui Fu , Jiangsheng Hu , Dongdong Zhang , Haiyan Zhu

Additive categories play a fundamental role in mathematics and related disciplines. Given an additive category equipped with a biadditive functor, one can construct its category of extensions, which encodes important structural information.…

Category Theory · Mathematics 2023-10-30 Raphael Bennett-Tennenhaus , Johanne Haugland , Mads Hustad Sandøy , Amit Shah

We extend results of Br\"ustle-Yang on ideal quotients of 2-term subcategories of perfect derived categories of non-positive dg algebras to a relative setting. We find a new interpretation of such quotients: they appear as prototypical…

Representation Theory · Mathematics 2024-01-22 Xin Fang , Mikhail Gorsky , Yann Palu , Pierre-Guy Plamondon , Matthew Pressland

A notion of $n$-cotorsion pairs in an extriangulated category with enough projectives and enough injectives is defined in this article. We show that there exists a one-to-one correspondence between $n$-cotorsion pairs and $(n+1)$-cluster…

Representation Theory · Mathematics 2019-08-01 Panyue Zhou

In this work we introduce the notion of higher $\mathbb{E}$-extension groups for an extriangulated category $\mathcal{C}$ and study the quotients $\mathcal{X}_{n+1}^{\vee}/[\mathcal{X}]$ and $\mathcal{X}_{n+1}^{\wedge}/[\mathcal{X}]$ when…

Representation Theory · Mathematics 2023-09-27 Mindy Y. Huerta , Octavio Mendoza , Corina Sáenz , Valente Santiago

We say that a projective class in a triangulated category with coproducts is perfect if the corresponding ideal is closed under coproducts of maps. We study perfect projective classes and the associated phantom and cellular towers. Given a…

Category Theory · Mathematics 2010-04-01 George Ciprian Modoi

For the module category of an Artin algebra, we generalize the notion of torsion pairs to ideal torsion pairs. Instead of full subcategories of modules, ideals of morphisms of the ambient category are considered. We characterize the…

Representation Theory · Mathematics 2026-02-25 Kevin Schlegel

The aim of this paper is to develop a framework for localization theory of triangulated categories $\mathcal{C}$, that is, from a given extension-closed subcategory $\mathcal{N}$ of $\mathcal{C}$, we construct a natural extriangulated…

Category Theory · Mathematics 2025-05-22 Yasuaki Ogawa

We take a novel lattice-theoretic approach to the $\tau$-cluster morphism category $\mathfrak{T}(A)$ of a finite-dimensional algebra $A$ and define the category via the lattice of torsion classes $\mathrm{tors } A$. Using the lattice…

Representation Theory · Mathematics 2025-02-26 Maximilian Kaipel

Let $\mathcal{E}=(\mathcal{A},\mathcal{S})$ be an exact category with enough projectives $\mathcal{P}$. We introduce the notion of support $\tau$-tilting subcategories of $\mathcal{E}$. It is compatible with existing definitions of support…

Representation Theory · Mathematics 2024-01-30 Jixing Pan , Yaohua Zhang , Bin Zhu

We present a setting for the study of torsion theories in general categories. The idea is to associate, with any pair ($\mathcal T$, $\mathcal F$) of full replete subcategories in a category $\mathcal C$, the corresponding full subcategory…

Category Theory · Mathematics 2022-01-04 Alberto Facchini , Carmelo Finocchiaro , Marino Gran

Nakaoka and Palu introduced the notion of extriangulated categories by extracting the similarities between exact categories and triangulated categories. In this paper, we study cotorsion pairs in a Frobenius extriangulated category $\C$.…

Representation Theory · Mathematics 2018-07-20 Wen Chang , Panyue Zhou , Bin Zhu

In this paper we introduce $n\mathbb{Z}$-abelian and $n\mathbb{Z}$-exact categories by axiomatising properties of $n\mathbb{Z}$-cluster tilting subcategories. We study this categories and show that every $n\mathbb{Z}$-cluster tilting…

Category Theory · Mathematics 2022-02-15 Ramin Ebrahimi , Alireza Nasr-Isfahani